The present invention relates to a regulated power supply system with high input voltage dynamics.
More particularly, the invention relates to a power supply system including a shared-inductance buck/boost transformer and including at least two controllable semiconductor switching members, one associated with the buck function of the transformer and the other with the boost function of said transformer.
It is known that such power supply systems can have three operating modes, i.e. a buck mode, a boost mode, and a buck/boost mode.
These three operating modes then require the use of three different implemented control logics and a switch between these different control logics.
In the state of the art, one for example monitors the voltage difference between the input and output of the power supply system and then chooses the best suited control law. This makes it possible to obtain the desired operation to lower or raise the voltage or to obtain an optimal output.
This solution is already being implemented in commercial power supply systems such as the LINEAR TECHNOLOGY LTC3780 controllers.
However, it has a certain number of drawbacks.
Because there are in fact three operating modes, there are also three implemented control logics. During operation, the system operating only in one of the three modes most of the time, if the control breaks down in one of the other two modes, the breakdown may be hidden. There is then a possibility of having a latent breakdown that is not detected in the nominal operating mode, but that can cause unavailability of the system in certain transitional events.
However, such systems may for example be implemented in aeronautics applications, where one can see that such a drawback can result in major problems.
Furthermore, the logic of going from one control mode to the other is done based on a comparison with hysteresis. This results in several drawbacks, i.e. the operating mode in the transitional areas depends on the progression direction of the input voltage, there is a risk of instability if the hysteresis of the comparison is not great enough, and the discontinuity of the operating mode risks having an impact on the output voltage during the transitional phases.
The aim of the invention is therefore to resolve these problems.